(For gay couples, it's more like two out of every three).
The apps have been surprisingly successful -- and in ways many people would not expect.
In fact, by several measures, online dating has proved even more useful — both to individuals and society — than the traditional avenues it has replaced.
I wondered to myself, is this what online dating has done to us?
Is it creating a new reality in which people actively avoid real-life interactions?
Of course, others have worried about these sorts of questions before.
But the fear that online dating is changing us, collectively, that it's creating unhealthy habits and preferences that aren't in our best interests, is being driven more by paranoia than it is by actual facts.
"There are a lot of theories out there about how online dating is bad for us," Michael Rosenfeld, a sociologist at Stanford who has been conducting a long-running study of online dating, told me the other day.
"And mostly they're pretty unfounded." Rosenfeld, who has been keeping tabs on the dating lives of more than 3,000 people, has gleaned many insights about the growing role of apps like Tinder.
They are important today — roughly one of every four straight couples now meet on the Internet.
A couple of months ago, I was sitting at a bar minding my own business when the woman next to me did something strange.
Surrounded by potential partners, she pulled out her phone, hid it coyly beneath the counter, and opened the online dating app Tinder.
On her screen, images of men appeared and then disappeared to the left and right, depending on the direction in which she wiped.
I felt a deep sense a rejection -- not personally, but on behalf of everyone at the bar.